Survivors of the most common form of childhood leukemia should be considered cured if they live for 10 years without a relapse, new research concludes.
Once thought untreatable, more than 80 percent of patients with acute lymphoblastic leukemia now survive at least five years. But they are still at risk for a return of the blood cancer, developing second cancers or other complications, making the definition of a cure uncertain.
Researchers at St. Jude Children's Research Hospital in Memphis, Tenn., studied 856 patients who survived at least 10 years without a relapse and concluded that patients who weren't treated with radiation and are in remission for 10 years can expect to live normal lives.
``Now we can say for certain, and we can reassure long-term survivors, that they are cured of their leukemia,'' said Dr. Ching-Hon Pui, who led the study published in Thursday's New England Journal of Medicine.
Survivors who received radiation should make sure they get annual checkups, Pui said.
A second study in the journal found no evidence of serious psychiatric disorders among childhood cancer survivors in Denmark, except for those with brain tumors.
The St. Jude study included patients treated there between 1962 and 1992. Four patients had a reoccurrence of leukemia and there were 44 cases of second tumors, most of them related to radiation treatment and mostly non-cancerous or low-grade malignancies.
Standard treatment for leukemia used to include radiation treatment to prevent it from spreading to the brain or spinal cord, Pui said. Its use has diminished, and St. Jude has stopped using radiation treatment in favor of intensive chemotherapy, he said.
The researchers also looked at quality-of-life issues and found the rate of death, employment and marriage in the group that wasn't given radiation was comparable to the general population. In those who received radiation, the rate of death and unemployment was slightly higher and the marital rate for women was lower than for the general population.
Obtaining health insurance can be a problem for cancer survivors. The study showed insurance coverage for all the patients was similar to the general population, although some were denied insurance, charged high rates or had restricted plans.
Dr. Smita Bhatia of the City of Hope Cancer Center in Duarte, Calif., said the study defines what doctors have long suspected and gives patients an important definition of a cure.
``It is a life-turning event if you tell the patient that they are cured _ that essentially they can put the disease behind,'' she said.